Which vitamin is required for the conversion of homocysteine to methionine?

Vitamin B12 plays a crucial role in the conversion of homocysteine to methionine. This reaction is essential for maintaining normal levels of homocysteine in the body, as elevated homocysteine levels can be associated with an increased risk of cardiovascular diseases.

In this conversion process, Vitamin B12 acts as a cofactor for the enzyme methionine synthase, which directly facilitates the transfer of a methyl group to homocysteine, thus forming methionine. Methionine is an important amino acid that plays various roles, including acting as a precursor for other important compounds and participating in the process of methylation, which is critical for regulating gene expression and other biological processes.

While Vitamin B6 is also involved in amino acid metabolism and can be part of the homocysteine metabolism pathway (it facilitates the conversion of homocysteine to cysteine), it does not directly participate in the conversion to methionine as Vitamin B12 does. Other options, such as Vitamin C and riboflavin, are not directly involved in this particular biochemical conversion.